Localized measurement and mapping of tissue nonlinear elasticity

组织非线性弹性的局部测量和绘图

• 批准号: 9196131
• 负责人: Azra Alizad
• 金额: $ 20.99万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9196131
• 关键词: Acoustics; Adipose tissue; Behavior; Benign; Biological Markers; Breast; Clinic; Data; Development; Diagnostic; Diagnostic Imaging; Diagnostic Procedure; Effectiveness; Elasticity; Evaluation; Fibroadenoma; Focused Ultrasound; Future; Geometry; Goals; Histocompatibility Testing; Hydrostatic Pressure; Image; Investigation; Laboratories; Lesion; Magnetic Resonance Imaging; Malignant - descriptor; Malignant Neoplasms; Mammary Gland Parenchyma; Maps; Mass in breast; Measurement; Measures; Mechanics; Medicine; Methodology; Methods; Modality; Monitor; Organ; Outcome; Palpation; Pathologic; Pathology; Performance; Pilot Projects; Property; Publishing; Radiation; Research; Resolution; Sampling; Sensitivity and Specificity; Specificity; Speed; Staging; Techniques; Testing; Time; Tissue Sample; Tissues; Translations; Ultrasonography; Variant; abstracting; animal tissue; base; breast imaging; diagnostic biomarker; elastography; imaging modality; improved; in vivo; infiltrating duct carcinoma; innovation; interest; member; novel; novel diagnostics; physical property; radiation response; response; shear stress; skills; soft tissue; theories; tissue phantom; tool

Abstract Palpation has been used for hundreds of years in medicine to differentiate various types of tissues and masses within tissue. In technical terms, palpation can be defined as deformation of tissue in response to a force, which in linear mechanics is defined as tissue elasticity. The concept of tissue elasticity i.e. elastography has been the subject of intense investigations in the past two decades. However, recent studies have shown that tissue behaves nonlinearly at larger strains, whereby the nonlinear elasticity of tissue may carry important diagnostic information. The long-term objective of this research is the development of a novel diagnostic technique that (i) makes use of the acoustic radiation force (ARF) for noninvasive tissue interrogation, and (ii) deploys a novel coefficient of nonlinear tissue elasticity as a biomarker that is sensitive to tissue type. One possible application of the method, initiated in this study, is the differentiation of breast masses; however, the proposed method may find applications in other organs. The proposed study is made possible by the recent discovery by our research team that the magnitude of the ARF in soft tissues depends linearly on a particular coefficient of nonlinear tissue elasticity, hereon denoted by C – that quantifies the gain in shear wave speed due to increasing hydrostatic pressure. The basic idea behind the method is to act upon tissue by the ARF at a point of interest (e.g. inside a breast mass) and to monitor the ARF-generated generated shear waves via ultrasound. In this setting, the nonlinear modulus C can be computed from the amplitude of the observed shear waves — a claim that is supported by our preliminary data on tissue-mimicking phantoms and animal tissues. The proposed approach to nonlinear tissue elastography is novel in that: (a) it focuses on the volumetric-shear modulus C that has eluded previous studies, and (b) it enables, for the first time, local evaluation of nonlinear tissue elasticity with a spatial resolution given by the size of the focal region (order of mm). This makes it possible to locally measure C over the volume of the focal region using the ARF. For this reason, the proposed method is hereon referred to as nonlinear C-Elastography (CE). To assess the effectiveness of CE, we first propose to create well-characterized phantoms with (tissue-mimicking) lesions and create their C-images to be compared with the respective linear (e.g. shear modulus) elastograms. The last stage of our study would focus on the ex-vivo testing of breast masses, through which we will be able to correlate the CE results to tissue pathology and assess the overall effectiveness of CE. Successful completion of this research will spur the development of a noninvasive, diagnostic tool that may have significant impact in early differentiation of breast masses and potentially pathologies in other organs.

摘要 触诊已经在医学上使用了数百年，以区分各种类型的组织和肿块 组织内。在技术术语中，触诊可以被定义为组织响应于力的变形， 其在线性力学中被定义为组织弹性。组织弹性的概念，即弹性成像， 在过去的二十年里一直是密集调查的主题。然而，最近的研究表明， 组织在较大的应变下表现为非线性，由此组织的非线性弹性可以携带重要的 诊断信息。这项研究的长期目标是开发一种新的诊断方法， 一种技术，（i）利用声辐射力（ARF）进行非侵入性组织询问，以及（ii） 部署了一种新的非线性组织弹性系数作为对组织类型敏感的生物标志物。一 在这项研究中开始的该方法的可能应用是乳腺肿块的分化;然而， 所提出的方法可以在其他器官中找到应用。最近的研究使这项研究成为可能。 我们的研究团队发现，软组织中ARF的大小线性依赖于特定的 非线性组织弹性系数，在此由C表示，其量化剪切波速度的增益 由于静水压力的增加。该方法背后的基本思想是通过ARF以一定的速度作用于组织。 感兴趣点（例如，乳房肿块内部），并通过以下方式监测ARF产生的剪切波 超声.在这种情况下，非线性模量C可以从所观察到的剪切的幅度计算 波-这一说法得到了我们对组织模拟幻影和动物组织的初步数据的支持。 所提出的非线性组织弹性成像方法的新颖之处在于：（a）它侧重于体积剪切 模量C，这已经回避了以前的研究，和（B）它使，第一次，局部评估的非线性 具有由聚焦区域的尺寸给出的空间分辨率（mm量级）的组织弹性。这使得 可以使用ARF在聚焦区域的体积上局部测量C。基于这个理由，拟议 该方法在本文中被称为非线性C-弹性成像（CE）。为评估行政长官的成效，我们首先 建议创建具有（组织模拟）病变的良好特征的体模，并创建其C图像， 与相应的线性（例如剪切模量）弹性图相比。我们研究的最后阶段将集中在 在乳房肿块的离体测试中，我们将能够将CE结果与组织相关联 病理学检查，并评估CE的总体有效性。这项研究的成功完成将推动 开发一种非侵入性的诊断工具，可能对早期分化有重大影响。 乳房肿块和其他器官的潜在病理。